Sound amplifying horn



y 8. 9 G. 6'. DE ANDIA-YRARRAZAVAL SOUND AMPLIFYING HORN Filed Dec. 9, 1925 Gabhe/ Gonzo/c2. do Jud/a War/142a ra/ Patented July 28, 1931 UNITED STATES PATENT QFHCE SOUND AMPLIFYING Application filed December 9, 1925, Serial No. 74,365, and in Great Britain January 20, 1925.

This invention has reference to sound amplifying horns for use for example in connection with phonographs, loud speaking devices of wireless receiving apparatus and the like.

The object of the invention is to provide relatively cheap, robust and ornamental sound amplifying horns of great efliciency as compared with sound amplifying horns of similar size as heretofore usually constructed.

For this purpose, according to the invention, the improved sound amplifying horn comprises a tube or sound conduit, preferably a frustum-shaped tube, axially located within a sound reflecting bell opposite to the inner end of which the inner end of the said tube or conduit opens, the said sound reflecting bell being surrounded by a hermetically sealed air chamber formed by and between the outer surface of the bell wall and a casing within which the body of the bell is secured. The sound reflecting bell may have in its vertex the form of a cone facing towards the tube or sound conduit opening obtaining by this arrangement that sound Waves be diverted with a greater extension towards the bell walls, thus, considerably reducing the interference of sounds that would result from reflecting in the tube or sound conduit the sound waves delivered by the conduit against the reflecting bell. I

The air in said chamber constitutes an air cushion around the reflecting bell that is found greatly to enhance the sound aniplifying properties of the improved horn. In some cases it will not be found necessary that the said. air chamber be hermetically closed, the air may circulate therein through openings in the casing wall inclicated at 10 in Fig. 3. The mouth or lip of the sound reflecting bell is connected to the external casing in such manner as to provide a continuation of the bell.

The external casing may be of any desired shape and may be so formed as to constitute a decorativefigure or article of utility.

The external casing and preferably the sound reflecting bell are formed of an appropriate material capable of being moulded, and the invention furth m r id in a method of producing the improved sound amplifying horn according to which the external casing the sound reflecting bell and the central sound tube 01 conduit are all secured together in proper association to form a complete single unit in the operation of moulding.

Any suitable material capable of being moulded may be used in the construction of the improved sound amplifying horn, such for example as a metallic cement that is to say, a cement containing powdered c3 metal, but the material should preferably be relatively light and of not too dense a character.

Although metal is not found to be so good for the purpose as a plastic cement, or the is like, the invention not restricted to materials other than metal as there may be cases in which metal might be found satisfactory.

The shape of the outer casing and the [5; capacity of the air chamber surrounding the sound reflecting hell a e immaterial to the invention which, as before stated, consists in the provision, of the air cushion V1.10 matter how the same is produced.

It may in some cases be an advantage to make the sound reflecting bellof relatively thin material and as it is well protected by the external casing rigidly secured .to the same, it is not liable to be damaged :35 however thin it may be made, but it will be found that an increased efficiency arises from the provision of the air cushion irrespective of the thickness of the material of which the reflecting bell is formed. a

Conveniently the frustum .or other shaped tube .or sound conduit is connected to and properly positioned by a grid or spider located atthemouth of the sound reflecting bell, the said grid or spider with the tube or conduit secured thereto bein rigidly secured to the sound reflecting bell and to the external casing by the operation of moulding the outer casing which, as before stated,

may be in the shape of a decorative figure.

For a better explanation reference is made graphically shown in the annexed drawto the accompanying drawings, showing the mgs. different parts that constitute the subycct Dated in Barcelona 21st November, 1925.

. matter of this invention. GABRIEL GONZALEZ Fig. l is a sectional elevation showing one DE ANDIA-YRARRAZAVAL.

7 Fig. 1 showing an arrangement wherein the form of the invention.

Fig. 2 is a perspective view of another term of the invention.

Fig. 3 is a fragmentary detail similar to outer casing is perforated and the bell provided with a cone.

In Figure l is the tube or sound conduit which is secured to the wall of the external '3 casing A and the bell wall B, having its month situated in front of the vertex of the said sound reflecting bell.

The sound reflecting bell 2 is joined to the external casing at the edges C and D, an air chamber or cushion, that is, the space existing between the bell and the case walls C, E, F and D being thus formed. At C and D may be seen the curved line connecting the hell edges to the external casing surfaces. This curved line renders the apparatus an endless horn.

As stated in the present specification the tube or sound conduit may be conveniently placed and arranged according to the shape of the complete unit that is desired.

Figure 2 illustrates a modification of the invention showing one manner of supporting the sound conduit to the bell by means I of a grid or spider.

In details of construction variations may we be made without departure from the invcntion.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that What I claim is 1. A sound amplifier comprising a sound tube, a sound reflecting bell surrounding the said sound tube, and a casing surrounding the said bell to provide an air space around and at the back of the said bell, said casing being connected with the front end or lip of the bell to provide a continuation of the bell.

2. A sound amplifier comprising a sound tube, a sound reflecting bell surrounding the said sound tube, and a casing surrounding the said bell to provide an air space around and at the back of the said bell, the lip of the said bell being returned upon itself and continued to form the casing surrounding the said bell, the said bell and said casing constituting a unitary structure.

3. A sound amplifier as claimed in claim 1, the open end of said sound tube being in axial alignment with said sound reflecting bell, and a spider secured to the open end of said bell for supporting said sound tube in fixed relation to said bell.

As stated in the present specification and a 

